Autonomism is a political doctrine which supports acquiring or preserving political autonomy of a nation or a region. It is not necessarily opposed to federalism, and souverainism necessarily implies autonomism, but not vice versa.

The 26 Cantons of Switzerland demonstrate autonomism in a federal state. The Swiss Federal Constitution declares the cantons to be sovereign to the extent their sovereignty is not limited by federal law. The cantons also retain all powers and competencies not delegated to the Confederation by the Constitution.